#lang racket
(require r5rs)
(define first car)
(define second cadr)
(define third caddr)
(define fourth cadddr)
(define rest cdr)
(print-as-expression #f)
(print-mpair-curly-braces #f)

(define lst1 '(1 2 3))
(define lst2 '(4 5 6))

(define lst3 (append lst1 lst2))
lst3
(set-car! lst3 2)
lst3

(set-car! lst1 4)
lst3

(define lst4 lst3)
lst4

(set! lst4 '(1 2))
(empty? lst4)
(rest lst4)
(rest (list 1 2 3))

